Open VSX extension squatting: what it means for CI and repo identity

TL;DR: 77 counterfeit Open VSX extensions copied real VS Code Marketplace names and namespaces, and 19 of them collected git and CI identity such as repository paths, branch data, and project identifiers, according to Manifold Security research. Name-based installation now creates a trust gap because automated tools can resolve the wrong package before any human review occurs.

Editorial analysis by NHI Mgmt Group, based on content published by Manifold Security: “77 "Evil Twin" Open VSX Extensions: 19 Copy Private Repo and CI Data to a New Domain”.

Practitioner guidance

• Tighten extension allowlisting for automated installs Require explicit approval for editor extensions installed by devcontainers, images, or agent workflows, and restrict those workflows to verified publishers and approved registries.
• Audit developer and build images for squatted package names Search .vscode/extensions.json, .devcontainer/devcontainer.json, and image build logic for extension IDs that resolve to Open VSX or other alternate registries without publisher verification.
• Treat workspace metadata as sensitive Classify git remote URLs, branch names, repository paths, and CI project identifiers as sensitive telemetry when they appear in editor or extension data flows.

Bottom line: Counterfeit extensions can weaponise ordinary package resolution when automation trusts names more than publishers.

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